In symptoms positive groups of gerbils significant decrease of glucose and glycogen and increase of lactate and pyruvate was obtained 5 minutes after onset of ischemia in all brain structures of the hemisphere ipsilateral to the occlusion. The lowest content of glycogen was obtained 1 hour after carotic artery occlusion. Lactate and pyruvate concentrations increased and that of glucose decreased with duration of ischemia. Nine hours after onset of ischemia glycogen was histochemically observed in areas bordering the infarction. In recovery from one hour ischemia, in symptoms positive animals, levels of glucose, pyruvate and gylcogen were not different from the controls 1 hour after the occlusion was removed. Lactate was significantly elevated even after 20 hours of recovery. Glycogen content was higher at that time and was elevated even 1 week after the release.